There is an unmet need for a quick, reliable method to assess pulpal blood flow. Our long-term goal is to develop a quick, inexpensive, reliable method to enable dentists and endodontists to (i) assess pulpal vitality, (ii) make an informed decision on the appropriate treatment plan, and (iii) monitor treatment response for each individual tooth. Having determined the feasibility of dental Laser Speckle Imaging (dLSI)-based pulpal diagnosis in our preliminary studies, the overall objective of this application is to quantiy the performance of the dLSI method developed jointly by the PIs to assess pulpal blood flow and viability in a quick repeatable fashion. Our central hypothesis is that dLSI measurement of pulpal blood flow results in a positive and negative predictive value of pulpal vitality that excees the values found with either an Electrical Pulp Tester (EPT) or thermal tests. The rationale that underlies the proposed research is that we expect to demonstrate that dLSI is a reliable in-vivo method to assess pulpal vitality. Guided by strong preliminary data, we will test the hypothesis by pursuing the following two Specific Aims: 1) Develop second-generation, clinic-friendly dLSI instrument, and 2) Determine the positive and negative predictive values associated with in-vivo dLSI, EPT, and thermal tests, to assess pulpal vitality. Under the first aim, we will couple computational modeling with our extensive previous experience with clinical LSI instrument design, to develop a second- generation dLSI instrument that is designed for use in the oral cavity. Under the second aim, we will deploy this dLSI instrument to a nearby endodontic clinic to perform a clinical study and assess the capabilities of dLSI for pulpal vitality testing. The approach is innovative, in our opinion, because we propose development of an imaging approach and technology that is substantially different from that used in the oral cavity by past investigators. The proposed research is significant, because it is a first step towards development of a simple, low-cost, quick method that enables dentists and endodontists finally to assess accurately pulpal health status.